U.S. patent application number 14/915578 was filed with the patent office on 2016-08-18 for electrical power generation.
The applicant listed for this patent is GE OIL & GAS UK LIMITED. Invention is credited to Richard Clements.
Application Number | 20160237979 14/915578 |
Document ID | / |
Family ID | 49727080 |
Filed Date | 2016-08-18 |
United States Patent
Application |
20160237979 |
Kind Code |
A1 |
Clements; Richard |
August 18, 2016 |
ELECTRICAL POWER GENERATION
Abstract
A method and apparatus for generating electrical power are
disclosed. The method includes the steps of turning turbine blades
of at least one turbine provided at a region of a subsea pipe or
umbilical via a respective motion of seawater through a swept area
associated with the turbine blades and generating electrical power
responsive to turning of the turbine blades.
Inventors: |
Clements; Richard; (Durham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GE OIL & GAS UK LIMITED |
Bristol |
|
GB |
|
|
Family ID: |
49727080 |
Appl. No.: |
14/915578 |
Filed: |
September 23, 2014 |
PCT Filed: |
September 23, 2014 |
PCT NO: |
PCT/GB2014/052896 |
371 Date: |
February 29, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F03B 13/10 20130101;
Y02E 10/30 20130101; F05B 2220/602 20130101; Y02E 10/22 20130101;
H02K 7/1823 20130101; F03B 13/00 20130101; H02K 5/132 20130101;
Y02E 10/32 20130101; F05B 2240/97 20130101; Y02B 10/50 20130101;
F05B 2240/911 20130101; F05B 2220/7068 20130101 |
International
Class: |
F03B 13/10 20060101
F03B013/10; H02K 5/132 20060101 H02K005/132; H02K 7/18 20060101
H02K007/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 21, 2013 |
GB |
1318560.8 |
Claims
1. A method of generating electrical power, comprising the steps
of: turning turbine blades of at least one turbine provided at a
region of a subsea pipe or umbilical via respective motion of
seawater through a swept area associated with the turbine blades;
and
2. The method as claimed in claim 1, further comprising the steps
of: generating electrical power locally via the turbine on the pipe
or umbilical and providing the power to auxiliary equipment on or
proximate to the said region of the pipe or umbilical.
3. The method as claimed in claim 1, further comprising the steps
of: providing the respective motion of seawater by continuously
moving the turbine blades through a body of seawater.
4. The method as claimed in claim 3, further comprising the steps
of: moving the turbine blades by moving the region of the pipe or
umbilical to which the turbine is secured through the body of
seawater.
5. The method as claimed in claim 3, further comprising the steps
of: driving a driveshaft of the turbine as the turbine blades
rotate; and generating electrical power via a permanent magnet
synchronous generator (PMSG) of the turbine responsive to rotation
of the driveshaft.
6. (canceled)
7. (canceled)
8. The method as claimed in claim 1, further comprising the steps
of: providing the respective motion of seawater by moving seawater
with respect to the pipe or umbilical.)
9. The method as claimed in claim 8, further comprising the steps
of: generating electrical power when a current flows in the
seawater.
10. (canceled)
11. (canceled)
12. The method as claimed in claim 2, further comprising the steps
of: providing the power via a contactless connection between the
turbine and the auxiliary equipment.
13. A method of providing electrical power to auxiliary equipment,
comprising the steps of: via at least one turbine provided at, and
movable with, a region of a pipe or umbilical at a subsea location,
generating electrical power; and directly or indirectly powering
auxiliary equipment via the generated power.
14. The method as claimed in claim 13, further comprising:
generating electrical power locally via the turbine on the pipe or
umbilical and providing the generated power locally to auxiliary
equipment proximate to said region of the pipe or umbilical.
15. The method as claimed in claim 13, further comprising the steps
of: powering the auxiliary equipment by providing the generated
power to the auxiliary equipment via an electrical connection
simultaneously as the power is generated.
16. The method as claimed in claim 15, further comprising the steps
of: providing the power to the auxiliary equipment via a permanent
or contactless connection.
17. The method as claimed in claim 14, further comprising the steps
of: powering the auxiliary equipment by charging a power source
with the generated power and subsequently providing power to the
auxiliary equipment from the power source.
18. (canceled)
19. The method as claimed in claim 13, further comprising:
generating electrical power comprises generating an extra low
voltage of about around 24 volts RMS or less.
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. A turbine for generating electrical power, comprising: a
plurality of rotatable turbine blades associated with a swept area;
a driveshaft that rotates as the turbine blades turn; and a power
generator that generates electrical power responsive to rotation of
the driveshaft; wherein the turbine is connectable to a region of a
subsea flexible pipe or umbilical to generate power via respective
motion of seawater through said swept area.
25. The turbine as claimed in claim 24, further comprising: the
turbine generates electrical power locally at the pipe or umbilical
and is connected to auxiliary equipment on or proximate to said a
region.
26. (canceled)
27. (canceled)
28. The turbine as claimed in claim 24, further comprising: each of
the blades has a first and a further end and the turbine comprises
a first rotatable blade support connected to all of the first ends
of the blades and a further rotatable blade support connected to
all the further ends of the blades; and each blade support is
located with respect to the pipe or umbilical via a ring connector
and a bearing element between the ring connector and the blade
support.
29. The turbine as claimed in claim 24, further comprising: the
power generator comprises a permanent magnet synchronous generator
(PMSG) having permanent magnets on a generator end region of said
drive shaft.
30. (canceled)
31. The turbine as claimed in claim 24, where in the power
generator is located in or on an end fitting of a flexible
pipe.
32. The apparatus as claimed in claim 24 wherein the pipe is a
flexible pipe or steel catenary riser (SCR).
33. (canceled)
34. (canceled)
35. (canceled)
Description
[0001] The present invention relates to a method and apparatus for
generating electrical power. In particular, but not exclusively,
the present invention relates to a method of generating electrical
power by turning blades of a turbine carried on a subsea pipe or
umbilical via motion of seawater through a swept area associated
with the turbine blades.
[0002] Traditionally, flexible pipe is utilised to transport
production fluids, such as oil and/or gas and/or water, from one
location to another. Flexible pipe is particularly useful in
connecting a subsea location to a further subsea location or a sea
level location. Flexible pipe is generally formed as an assembly of
a segment of flexible pipe body and one or more end fittings in
which ends of the flexible pipe body are terminated. The pipe body
is typically formed as a composite of tubular layers of material
that form a fluid and pressure containing conduit. The pipe
structure allows large deflections without causing bending stresses
that impair the pipe's functionality over a desired lifetime.
Flexible pipe may be utilised as a flow line at a subsea location
and alternatively may be used as a jumper or riser or the like.
[0003] Other elongate and to some extent flexible elements are
known that can be used at subsea locations. For example umbilicals
are utilised to carry control wires or power cables or the like
from one location to another and these are typically protected via
an outer sheath.
[0004] Traditionally metal pipe is also utilised to transport
production fluids, such as oil and/or gas and/or water from one
location to another. Metal pipe is locally rigid but because of the
large lengths of the pipe can to some extent be flexible. Steel
catenary risers (SCRs) are an example of the use of metal pipes in
subsea locations.
[0005] It is known that from time to time auxiliary equipment is
located at a subsea location and that such auxiliary equipment
requires electrical power to operate. For example monitoring
systems are often used to monitor one or more operational
parameters associated with a pipeline or other structure and these
systems typically require sensors and/or analysis equipment which
require power. Conventionally such auxiliary equipment has been
provided with power locally by an exhaustible power source such as
a battery which provides the equipment with a requisite amount of
power for a predicted lifetime. However such limited power
lifetimes can reduce the overall utilisation of auxiliary equipment
and can lead to a requirement for refit of a new power source which
can be inconvenient and/or costly.
[0006] As an alternative to providing a local temporary power
source it is known that an electrical connection can be made to the
auxiliary equipment at a particular given location with the
connection leading from that location typically to a remote
location such as an overland or above sea level power source. Such
mechanisms for power delivery enable auxiliary equipment to
function over long periods of time but can cause problems. For
example electrical connectors of great length can be required.
These can be costly and are prone to failure and/or damage. Equally
if an onshore or above sea level source of energy fails then the
auxiliary equipment connected to it can cease to function.
[0007] It is an aim of the present invention to at least partly
mitigate the above-mentioned problems.
[0008] It is an aim of certain embodiments of the present invention
to provide a method and apparatus which can generate electrical
power locally near a region of a subsea pipe or umbilical or other
such structure.
[0009] It is an aim of certain embodiments of the present invention
to endlessly generate electrical power via respective motion of sea
water through a swept area of turbine blades of a turbine which can
be located or is located subsea on a pipe or umbilical or other
such structure.
[0010] It is an aim of certain embodiments of the present invention
to provide dynamic control over the movement of a riser pipe in a
water column with an ability to generate power from the current
and/or tidal action experienced in the area.
[0011] It is an aim of certain embodiments of the present invention
to utilise the movement of a riser pipe in a water column as a
result of the current and/or tidal action experienced in the area
to generate power by means of turbines and associated turbine
blades positioned on and attached to the riser pipe.
[0012] It is an aim of certain embodiments of the present invention
to generate electricity locally in sufficient amounts to power
monitoring and communication systems and other such auxiliary
equipment to enable systems remote from more permanent power
reserves to operate independently of umbilical-like
connections.
[0013] It is an aim of certain embodiments of the present invention
to generate energy locally to power auxiliary equipment fitted to
pipes or umbilicals at a subsea location and whereby surplus energy
can be stored locally for future use.
[0014] According to a first aspect of the present invention there
is provided a method of generating electrical power, comprising the
steps of: [0015] turning turbine blades of at least one turbine
provided at a region of a subsea pipe or umbilical via respective
motion of seawater through a swept area associated with the turbine
blades; and [0016] generating electrical power responsive to
turning of the turbine blades.
[0017] Aptly, the method further comprises generating electrical
power locally via the turbine on the pipe or umbilical and
providing the power to auxiliary equipment on or proximate to the
said region of the pipe or umbilical.
[0018] Aptly, the method further comprises providing the respective
motion of seawater by continuously moving the turbine blades
through a body of seawater.
[0019] Aptly, the method further comprises moving the turbine
blades by moving the region of the pipe or umbilical to which the
turbine is secured through the body of seawater.
[0020] Aptly, the method further comprises driving a driveshaft of
the turbine as the turbine blades rotate; and [0021] generating
electrical power via a permanent magnet synchronous generator
(PMSG) of the turbine responsive to rotation of the driveshaft.
[0022] Aptly, the method further comprises driving the drive shaft
via a spur gear element driven by an internal or external gear
member of the turbine that moves with the turbine blades.
[0023] Aptly, the method further comprises supporting ends of the
turbine blades via a respective rotatable blade support secured to
the pipe or umbilical via a respective bearing element.
[0024] Aptly, the method further comprises providing the respective
motion of seawater by moving seawater with respect to the pipe or
umbilical.
[0025] Aptly, the method further comprises the steps of generating
electrical power when a current flows in the seawater.
[0026] Aptly, the method further comprises generating electrical
power via a generator having a stator and a rotor driven by a shaft
connected to the turbine blades.
[0027] Aptly, the method further comprises providing the power via
a permanent electrical connection between the turbine and the
auxiliary equipment.
[0028] Aptly, the method further comprises providing the power via
a contactless connection between the turbine and the auxiliary
equipment.
[0029] According to a second aspect of the present invention there
is provided a method of providing electrical power to auxiliary
equipment, comprising the steps of: [0030] via at least one turbine
provided at, and movable with, a region of a pipe or umbilical at a
subsea location, generating electrical power; and [0031] directly
or indirectly powering auxiliary equipment via the generated
power.
[0032] Aptly, the method further comprises generating electrical
power locally to auxiliary equipment proximate to said region of
the pipe or umbilical.
[0033] Aptly, the method further comprises powering the auxiliary
equipment by providing the generated power to the auxiliary
equipment via an electrical connection simultaneously as the power
is generated.
[0034] Aptly, the method further comprises providing the power to
the auxiliary equipment via a permanent or contactless
connection.
[0035] Aptly, the method further comprises powering the auxiliary
equipment by charging a power source with the generated power and
subsequently providing power to the auxiliary equipment from the
power source.
[0036] Aptly, the method further comprises charging at least one
battery element or at least one capacitor element.
[0037] Aptly, the method of generating electrical power comprises
generating an extra low voltage of about 24 volts rms or less.
[0038] Aptly, the method further comprises providing power to
auxiliary equipment comprising a monitoring system for the pipe or
umbilical.
[0039] Aptly, the method further comprises providing power to the
auxiliary equipment comprising a wireless communication unit
associated with a pipe or umbilical.
[0040] Aptly, the method further comprises providing power to
auxiliary equipment comprising at least one heating element located
at a region of the pipe or umbilical for preventing/reducing
hydrate formation and/or wax accumulation in the pipe or
umbilical.
[0041] Aptly, the method further comprises providing power to
auxiliary equipment comprising a valve element or choke element of
the pipe or umbilical.
[0042] According to a third aspect of the present invention there
is provided a turbine for generating electrical power, comprising:
[0043] a plurality of rotatable turbine blades associated with a
swept area; [0044] a driveshaft that rotates as the turbine blades
turn; and [0045] a power generator that generates electrical power
responsive to rotation of the driveshaft; wherein [0046] the
turbine is connectable to a region of a subsea flexible pipe or
umbilical to generate power via respective motion of seawater
through said swept area.
[0047] Aptly, the turbine generates electrical power locally at the
pipe or umbilical and is connected to auxiliary equipment on or
proximate to said a region.
[0048] Aptly, the auxiliary equipment comprises a power storage
device.
[0049] Aptly, the power storage device comprises at least one
rechargeable battery or capacitor.
[0050] Aptly, each of the blades has a first and a further end and
the turbine comprises a first rotatable blade support connected to
all of the first ends of the blades and a further rotatable blade
support connected to all the further ends of the blades; and [0051]
each blade support is located with respect to the pipe or umbilical
via a ring connector and a bearing element between the ring
connector and the blade support.
[0052] Aptly, the power generator comprises a permanent magnet
synchronous generator (PMSG) having permanent magnets on a
generator end region of said drive shaft.
[0053] Aptly, the drive shaft has a spur gear element at a blade
end region driven by an internal or external gear member that moves
with the turbine blade.
[0054] Aptly, the power generator is located in or on an end
fitting of a flexible pipe.
[0055] Aptly, the pipe is a flexible pipe or steel catenary riser
(SCR). Aptly, the umbilical comprises a cable for supplying
consumables.
[0056] According to a fourth aspect of the present invention there
is provided apparatus constructed and arranged substantially as
hereinafter described with reference to the accompanying
drawings.
[0057] According to a fifth aspect of the present invention there
is provided a method substantially as hereinafter described with
reference to the accompanying drawings.
[0058] Certain embodiments of the present invention provide a
method and apparatus for generating electrical power via a turbine
provided at a region of a subsea pipe or umbilical. Current or
tidal flow or movement of the pipe or umbilical with respect to a
local body of sea water can this be utilised to generate electrical
power locally at the pipe or umbilical.
[0059] Certain embodiments of the present invention enable
auxiliary equipment such as monitoring systems or communication
systems or the like to be powered locally at a subsea location
using local motion of a pipe or umbilical with respect to the
nearby sea water. This provides a more or less endless source of
electrical power for the auxiliary equipment without the need for
complex electrical connection systems or for batteries to be
replaced or recharged.
[0060] Certain embodiments of the present invention provide a
mechanism for generating electrical power at a subsea location. The
electrical power may be provided via a contactless connector to a
remotely operated vehicle (ROV) as required (on demand) without the
ROV needing to return to a surface location to receive updated
energy resource.
[0061] Certain embodiments of the present invention enable surplus
energy to be stored in batteries or capacitance devices or
transmitted via umbilicals to a platform/FPSO to supplement
existing power supplies and/or provide green power. Power may also
be directed downwards into a flow line pipe network for similar
purposes or for heating and/or monitoring systems or to operate
subsea equipment such as valves/chokes or the like.
[0062] Certain embodiments of the present invention provide a
renewable energy source which has so far been unexploited.
[0063] Certain embodiments of the present invention will now be
described hereinafter, by way of example only, with reference to
the accompanying drawings in which:
[0064] FIG. 1 illustrates flexible pipe body;
[0065] FIG. 2 illustrates use of a flexible pipe, umbilical and
SCR;
[0066] FIG. 3 illustrates a view of part of a turbine;
[0067] FIG. 4 illustrates an alternative view of part of a
turbine;
[0068] FIG. 5 illustrates a power generator of a turbine;
[0069] FIG. 6 illustrates permanent magnets of a PMSG type of power
generator; and
[0070] FIG. 7 illustrates an alternative view of a turbine.
[0071] In the drawings like reference numerals refer to like
parts.
[0072] Throughout this description, reference will be made to a
flexible pipe. It will be understood that a flexible pipe is an
assembly of a portion of pipe body and one or more end fittings in
each of which a respective end of the pipe body is terminated. FIG.
1 illustrates how a portion of pipe body 100 (referred to as a
segment) is formed from a combination of layered materials that
form a pressure-containing conduit. Although a number of particular
layers are illustrated in FIG. 1, it is to be understood that the
present invention is broadly applicable to use with coaxial pipe
body structures (or other similar elongate structures as later on
described) including one or more layers manufactured from a variety
of possible materials. For example, the pipe body may be formed
from metallic layers, composite layers, or a combination of
different materials. It is to be further noted that the layer
thicknesses are shown for illustrative purposes only.
[0073] As illustrated in FIG. 1, pipe body includes an optional
innermost carcass layer 101. The carcass provides an interlocked
construction that can be used as the innermost layer to prevent,
totally or partially, collapse of an internal pressure sheath 102
due to pipe decompression, external pressure, and/or tensile armour
pressure and mechanical crushing loads. The carcass layer may be a
metallic layer, formed from carbon steel, for example. Optionally
the carcass layer could also be formed from composite, polymer, or
other material, or a combination of materials. It will be
appreciated that flexible pipes can provide `smooth bore`
operations (i.e. without a carcass) as well as such `rough bore`
applications (with a carcass).
[0074] The internal pressure sheath 102 acts as a fluid retaining
layer and comprises a polymer layer that ensures internal fluid
integrity. It is to be understood that this layer may itself
comprise a number of sub-layers. It will be appreciated that when
the optional carcass layer is utilised the internal pressure sheath
is often referred to by those skilled in the art as a barrier
layer. In operation without such a carcass the internal pressure
sheath may be referred to as a liner.
[0075] A pressure armour layer 103 is a structural layer with
elements having a lay angle close to 90.degree. that increases the
resistance of the flexible pipe to internal and external pressure
and mechanical crushing loads. The layer also structurally supports
the internal pressure sheath, and is an interlocked construction of
wires wound with a lay angle close to 9.degree..
[0076] The flexible pipe body also includes an optional first
tensile armour layer 105 and optional second tensile armour layer
106. Each tensile armour layer is used to sustain tensile loads and
internal pressure. The tensile armour layer may be formed from a
plurality of metallic wires (to impart strength to the layer) that
are located over an inner layer and are helically wound along the
length of the pipe at a lay angle typically between about
10.degree. to 55.degree.. The tensile armour layers may be
counter-wound in pairs. The tensile armour layers may be metallic
layers, formed from carbon steel, for example. Optionally the
tensile armour layers may be formed from composite, polymer, or
other material, or a combination of materials.
[0077] The flexible pipe body shown also includes optional layers
104 of tape which each help contain underlying layers and may act
as a sacrificial wear layer to help prevent abrasion between
adjacent layers.
[0078] The flexible pipe body also includes optional layers of
insulation 107 and an outer sheath 108, which comprises a polymer
layer used to help protect the pipe against penetration of seawater
and other external environments, corrosion, abrasion and mechanical
damage.
[0079] Each flexible pipe thus comprises at least one portion or
segment of pipe body 100 together with an end fitting located at at
least one end of the flexible pipe. An end fitting provides a
mechanical device which forms the transition between the flexible
pipe body and a connector. The different pipe layers as shown, for
example, in FIG. 1, are terminated in the end fitting in such a way
as to transfer the load between the flexible pipe and the
connector.
[0080] FIG. 2 illustrates a riser assembly 200 suitable for
transporting production fluid such as oil and/or gas and/or water
from a subsea location 201 to a floating facility 202. For example,
in
[0081] FIG. 2 the subsea location 201 includes an end of a subsea
flow line. The flexible flow line 205 comprises a flexible pipe,
wholly or in part, resting on the sea floor 204 or buried below the
sea floor and used in a static application. The floating facility
may be provided by a platform and/or buoy or, as illustrated in
FIG. 2, a ship. The riser assembly 200 is provided as a flexible
riser, that is to say a flexible pipe 203 connecting the ship to
the sea floor installation. The flexible pipe may be a single
segment or multiple segments of flexible pipe body with end
fittings connected end-to-end. The floating facility includes a
ship power generator 210 and a battery bank 220 for supplying power
on board the floating vessel.
[0082] It will be appreciated that there are different types of
riser, as is well-known by those skilled in the art. Certain
embodiments of the present invention may be used with any type of
riser, such as a freely suspended riser (free, catenary riser), a
riser restrained to some extent (buoys, chains) or totally
restrained riser. Certain other embodiments of the present
invention can be used as flow lines or jumpers or the like.
[0083] FIG. 2 also helps illustrate how a steel catenary riser
(SCR) 230 can be utilised to connect a semi-submersible production
platform 240 or other structure to a seabed location. The
production platform 240 can be moored to the seabed and includes a
power generation unit 250 for powering on board equipment. It will
be appreciated that other floating platforms such as tension-leg
platforms (TLPs) can also be connected to a subsea location via a
pipe or other similar structure. FIG. 2 also helps illustrate how
an umbilical 260 can be connected from the floating platform 240 to
a subsea location 265. The umbilical can provide a wide range of
ancillary products and services. Other umbilicals which do not
extend all the way to a seabed are also used. For example an
umbilical can be used as an electrical cable to provide power from
one location to another. Optionally the umbilical can include
optical fibre cables. An umbilical includes an outer sheath and one
or more wires or lumens or conduits which extend along the length
of the umbilical.
[0084] According to certain embodiments of the present invention
the pipes, whether flexible or metal or umbilicals extend through a
body of sea water 280. Tides or currents may flow in the sea water
and movement of the pipe or umbilical can occur as the floating
surface vessel moves up and down on the surface of the sea.
[0085] FIG. 3 illustrates a turbine for generating electrical power
responsive to respective motion of the pipe or umbilical and the
sea water. The turbine 300 includes turbine blades (two shown in
FIG. 3) which are secured at respective ends to a first ring-like
blade support 320 and a further ring-like blade support 330. These
ring supports extend circumferentially around a pipe 200 and are
secured to an outer sheath of the flexible pipe or an end fitting
via a ring-like connector. The ring-like connector 340 shown
towards the top of FIG. 3 is fixedly secured to the pipe and a
bearing (not shown) allows the upper most shown blade support 320
to freely spin with respect to the flexible pipe 200. Likewise the
lower blade support 330 shown in FIG. 3 is secured via a bearing
(not shown) to a lower ring-like connector 350 which is likewise
secured to an outer sheath of the flexible pipe 200. Again it will
be appreciated that alternatively the turbine blades via the
connectors may be secured to an end fitting, for example at a
midline connection, of the flexible pipe, or indeed on a length of
rigid pipe section situated in an in-line relationship between two
flexible pipes, or alternatively to a rigid section of pipe
connected to at least one end fitting of a flexible pipe and
positioned in a co-axial relationship with said flexible pipe
(where the flexible pipe runs through a section of rigid pipe). It
will be appreciated that the connectors and supports enable the fan
blades to spin freely around the longitudinal axis associated with
the flexible pipe 200. The blades define a swept area as they
rotate and respective motion of the flexible pipe and body of sea
water in which the turbine blades are immersed causes rotatory
motion of the blades and the blade supports. Rotation of the blades
causes the lower blade support 330 shown in FIG. 3 to rotate and
this causes respective rotation of a drive shaft 360 shown in FIG.
3. The drive shaft 360 rotates about a longitudinal drive shaft
axis.
[0086] FIG. 4 illustrates an underside of the blade support 330
shown in FIG. 3. The blade support 330 includes a blade body 400
which is hollow and has an internal gear 410. Optionally a sealed
cover (not shown) is secured over the internal gear. As the blade
support 330 rotates the teeth 420 of the internal gear 410 rotate
and these drive corresponding teeth 430 of a spur gear 440 on the
end of the drive shaft 360. Thus as a result of respective motion
between the flexible pipe and a body of sea water in which the pipe
is immersed the drive shaft 360 is caused to spin.
[0087] FIG. 5 helps illustrate further parts of the turbine and in
more particular detail illustrates a permanent magnet synchronous
generator (PMSG) 500. Other types of power generator that convert
rotary motion to electrical power could be used. Also an optional
inverter can be used to generate power regardless of a direction of
rotation of the drive shaft. The drive shaft 360 is supported in a
rotor bearing 510 and rotation of the drive shaft 360 is controlled
by a brake 520 and pitch drive 530.
[0088] A synchronous generator 540 is used to generate electricity
responsive to rotatory motion of the drive shaft 360. The generated
power is connected to a frequency convertor 550 illustrated in FIG.
5 which includes a generator side convertor 555 and a line side
convertor 560. A convertor controller 565 is controlled by a
turbine control unit 570 which also controls the pitch drive. A
main circuit breaker 575 receives a control signal from the
convertor control unit 565 and an output of the frequency convertor
is fed via the main circuit breaker 575 to a line coupling
transformer 580 and medium voltage switch gear 585. The turbine for
generating electrical power thus includes the multiple rotatable
turbine blades and a drive shaft that rotates as the turbine blades
310 turn.
[0089] FIG. 6 helps illustrate how the central drive shaft 360 is
secured to permanent magnets 600 (four shown in FIG. 6) via a
rotatable mount 610. As the permanent magnets rotate they generate
a magnetic flux (illustrated by bold arrows) 620 and these generate
current in surrounding coils which are themselves made up from at
least one wire wound into said coils. The current flow is shown by
way of example in FIG. 6.
[0090] It will be appreciated that the shaft 360 and rotatable
mount 610 may be hollow sections directly coupled to either the
lower blade support 330 or the upper blade support 320, and the
ring-like connectors 340 and 350 could be configured to encapsulate
said spur on three sides and comprise the coils in which the
current is generated as the turbine rotates.
[0091] FIG. 7 illustrates a turbine for generating electrical power
responsive to respective motion of the pipe or umbilical and the
sea water. The turbine 700 includes turbine blades 710 (two shown
in FIG. 7) which are each secured at respective ends to a first
ring-like blade support 720 and a further ring-like blade support
(not shown). These ring supports extend circumferentially around a
pipe 200 and are secured to an outer sheath of the flexible pipe
(or alternatively an end fitting) via a respective ring-like
connector. The ring-like connector 740 shown in FIG. 7 is secured
to the pipe 200 and an inner bearing 745 and outer bearing 750
allows the blade support 720 to freely spin with respect to the
flexible pipe 200. It will be appreciated that a further ring-like
connector and bearings secure the remaining end (not shown in FIG.
7) blade support. It will be appreciated that the bearings 745 and
750 may be substituted for contactless supports or the like in
order to reduce or eliminate friction in the system and improve
efficiency. For example, bearings 745 and 750 may be replaced with
sets of additional permanent magnet pairs, each magnet in a pair
presenting the same polarity to it's partner in the pair; in each
pair one magnet is attached to, or embedded in the blade support
720 and the other attached to, or embedded in the ring-like
connector 740. It will be appreciated that alternatively the
turbine blades, via the connectors, could be secured to an end
fitting, for example at a midline connection of a flexible pipe or
indeed on a length of rigid pipe section situated in an in-line
relationship between two flexible pipes. Alternatively connection
can be made to a rigid section of pipe connected to at least one
end fitting of a flexible pipe and positioned in a co-axial
relationship with the flexible pipe.
[0092] As illustrated in FIG. 7 the connectors and supports enable
the fan blades to spin freely around the longitudinal axis
associated with the flexible pipe. The blades define a swept area
as they rotate and respective motion of the flexible pipe and body
of sea water in which the turbine blades are immersed causes
rotatory motion of the blades and the blade support. Rotation of
the blades causes the blade support 720 shown in FIG. 7 to rotate
and this causes respective rotation of an end 760 of the support
720 which is enveloped within an annular recess in the connector
740. The end 760 of the blade support 720 has permanent magnets 770
distributed circumferentially on an outer surface facing a radially
inner facing surface of the connector 740 in the recess of the
connector 740. Thus as the blades 710 rotate permanent magnets
which are secured in place around the periphery of the blade
support rotate within the recess in the connector. Multiple coils
780 are located in the connector 740 and are spaced
circumferentially around the whole circumference of the connector.
Thus as the permanent magnets are caused to rotate power is
supplied to connectors 790 for generating electrical power. It will
be appreciated that similar permanent magnets and coils and
connectors can of course be located at the remaining end (not
shown) of the turbine in addition to or as an alternative to those
shown in FIG. 7. Optionally the same permanent magnets 770 used in
the generation of power may also be lengthened to extend further
along the length of the end 760 of the support 720 in order for
them to be used as part of the contactless bearing system described
above, when opposed by suitably positioned pairings of magnets on
or in the connector 740.
[0093] A power generator 500 generates electrical power responsive
to rotation of the drive shaft. Whilst certain embodiments of the
present invention have been described by way of securing a turbine
to a flexible pipe it will be appreciated that certain other
embodiments of the present invention are broadly applicable to the
use of a turbine to generate electrical power when the turbine is
secured to a pipe of any type or umbilical or similar elongate
movable structure in the sea. Movement of a riser pipe or umbilical
in a water column generates power or alternatively movement of
water due to current or tidal action also creates power. The
electricity generated is sufficient to power monitoring and
communication systems and to enable remote wireless systems to
operate independent of umbilical connections. It will be
appreciated that other units can be connected into systems for
heating a pipe structure for the purpose of preventing hydrate
formation/wax accumulation in a pipe.
[0094] Throughout the description and claims of this specification,
the words "comprise" and "contain" and variations of them mean
"including but not limited to" and they are not intended to (and do
not) exclude other moieties, additives, components, integers or
steps. Throughout the description and claims of this specification,
the singular encompasses the plural unless the context otherwise
requires. In particular, where the indefinite article is used, the
specification is to be understood as contemplating plurality as
well as singularity, unless the context requires otherwise.
[0095] Features, integers, characteristics or groups described in
conjunction with a particular aspect, embodiment or example of the
invention are to be understood to be applicable to any other
aspect, embodiment or example described herein unless incompatible
therewith. All of the features disclosed in this specification
(including any accompanying claims, abstract and drawings), and/or
all of the steps of any method or process so disclosed, may be
combined in any combination, except combinations where at least
some of the features and/or steps are mutually exclusive. The
invention is not restricted to any details of any foregoing
embodiments. The invention extends to any novel one, or novel
combination, of the features disclosed in this specification
(including any accompanying claims, abstract and drawings), or to
any novel one, or any novel combination, of the steps of any method
or process so disclosed.
[0096] The reader's attention is directed to all papers and
documents which are filed concurrently with or previous to this
specification in connection with this application and which are
open to public inspection with this specification, and the contents
of all such papers and documents are incorporated herein by
reference.
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